On a recent sunny Saturday, two student volunteers from N.C. Central University ambled down streets in East Durham, clutching clipboards and reciting a short pitch on their cause. The pair, Bobby and Inobeme, took turns rapping on doors on Gary Street.

When either volunteer mentioned the word "census," residents at the door responded as if they wanted to end the conversation as soon as it had begun.

"I sent mine back already," one woman responded.

"We filled it out," another man said.

George McNeal, 58, was more obliging.

"Yeah, I always fill it out," McNeal said, as he stood in his driveway, unloading his car trunk. "Because that's how you get roads and everything. ... If you don't send it back, how are they going to know anything?"

The message from the U.S. Census Bureau clearly had reached McNeal, likely through the program's $133 million ad campaign, complete with some waggish television spots during prime events like the Golden Globe awards, the Superbowl and of late, the NCAA men's basketball tournament. The federal government is even hip to Twitter and YouTube this year as it vies to get more of the country's more than 300 million residents to confirm, for the record, that they exist.

The census form this year asks 10 questions about who lives at an address and their races and ages. The federal government collects the data every 10 years to measure the country's population and demographics. The information factors into hundreds of programs, from election districts to the number of students who receive free lunch at school. As of March 30, half of U.S. residents who received the form have returned them. Fifty-three percent in North Carolina have returned the forms, which the government wants sent back by April 1. (Forms will still be accepted after that date, but that is a target.)

But as always, there are factors threatening the accuracy of the 2010 Census count. This spring, the City of Durham has dispatched dozens of volunteers like Bobby and Inobeme door-to-door to increase Durham's participation, in hopes of eventually boosting incoming dollars for federal programs.

"We're talking about $400 million in service money that could be coming to the city and county," said Earl Phillips, assistant director of community engagement in the city's neighborhood improvement program. "It becomes incredibly important." He's even urging ministers to mention the census from the pulpit.

In the past two census counts, nearly a third of households nationwide have failed to return their forms. In 2000, 64 percent of households in North Carolina responded, just under the national return rate of 67 percent. Durham County residents performed a little better, with 68 percent of households mailing the forms back. But in a large chunk of Durham—11 areas or neighborhoods including Lakewood, Golden Belt, MacDougald Terrace and Southside—about half of residents responded. That's where Phillips is focusing volunteer efforts.

"There are a number of reasons that people don't respond to the census," said Sunshine Hillygus, associate professor of political science at Duke University, who four years ago published the book The Hard Count: The Social and Political Challenges of the 2000 Census. "Some people are unable to respond, and some people are unwilling."

Many illegal immigrants, who are required to fill out the form, fear that the government will use the information to deport them. Some are concerned their personal information could lead to racial profiling. Others are worried about identity theft. The Census Bureau has issued statements about the security of the info, as well as the fines and imprisonment that could result from unlawful access or use.

The most worrisome trend, Hillygus said, are the apparent lack of government trust and poor civic engagement that are sometimes to blame for a lack of response.

There are many who "don't think the government should have access to the information on the form. They think it's government intrusion."

Additionally, Hillygus said, certain groups, such as middle-class whites, were overcounted in the last census, while blacks and Hispanics were undercounted.

"Census figures are used to determine both power and money, both in political distribution and billions of dollars in government money," she said. "The fact that people are being undercounted has very high stakes."

Compounding the challenge of getting responses is the inclusion of the word "Negro," on question No. 9, which asks residents to identify their race.

The term appears on the same check-off category as "black" and "African-Am." Critics have called the term offensive because of its tie to slavery and the Jim Crow era. The Census Bureau has responded to the widespread disapproval, in part, by stating that the phrase "Black, African Am., or Negro" was used on the 2000 Census, and that in addition, more than 56,000 people wrote in "Negro" in a space reserved for respondents to write in their race.

Despite the fact that many are offended, this shouldn't be a reason for residents to skip the census, according to a joint statement from the National Association for the Advancement of Colored People (NAACP), the Leadership Conference on Civil and Human Rights and the National Coalition on Black Civic Participation.

"Our primary focus is on reducing the disproportionate undercount of people of color, language minorities, the poor, and young children that has plagued the census for many decades," the statement said. "The stakes are too high. No less than fair political representation and access to a fair share of the nation's public and private resources are riding on the 2010 count. We can't afford to sit this one out."

The NACCP is teaming up with the Tom Joyner Morning Show, a nationally syndicated radio program, on a tour of 14 cities to encourage census participation among African-Americans. It starts this week and includes stops in Charlotte on April 13 and Raleigh on April 14.

Durham's branch of the NAACP hasn't received any comments or complaints about the inclusion of the word "Negro," said local president Fred Foster Jr.

"Personally, I filled mine out and sent it on in," Foster said.

But there are some residents of Durham who were offended.

In fact, while they were on the streets for hours telling others to return their census forms, those two NCCU undergrads say they aren't sending theirs in. Both Bobby Rice-Bey, 38, and Inobeme Polk, 36, are black and say they were offended by the word Negro and that they won't check off a category that lists all three identifiers (African-American, black and Negro) on the same line.

"Historically, a Negro is a second-class citizen," said Rice-Bey, a political science major.

The pair said they're abstaining on principle, but not filling out the mail-in form doesn't mean you won't be counted, said Anthony Jones, a Census Bureau spokesman. In fact, the government will just spend more money—$52 a pop—to reach people who don't mail back their forms by sending a federal worker to those homes starting in May, Jones said.

So, Bobby and Inobeme might soon themselves receive a knock on the door and a short speech about the U.S. Census.